流固耦合作用下节理岩质边坡失稳过程的RFPA模拟分析

利用基于强度折减法的RFPA-Slope对渗流与应力耦合作用下的软弱互层岩质边坡稳定性进行了数值模拟分析,数值模拟不但直观形象地给出了边坡的渗流场、应力场、破坏区分布,而且得到了边坡滑移破坏面的萌生、扩展、贯通以及坡体整体失稳的渐进破坏过程,同时求得安全系数。并与无地下水的稳定性作了比较,结果表明,地下水渗流的作用使坡体位移增大,边坡安全系数减小,明显加大了滑坡范围。对实例的分析说明,RFPA-Slope能够较为准确地预测边坡潜在破坏面的形状与位置及计算相应的稳定安全系数,本文方法对于边坡,特别是对于复杂边坡的稳定性分析具有实用性。     

含不连续面巷道的动力破坏过程数值分析

利用新近开发的动态版岩石破裂过程分析系统RFPA2D模拟了动力扰动下含不连续面巷道的破坏过程,从细观角度分析了不同宽度不连续面的岩石巷道在动力扰动下破坏的规律,并和未含不连续面巷道结构的相应情况进行比较,探讨了含不连续面巷道结构在动载荷作用下的力学特性,结果表明不连续面对应力波衰减作用明显,对巷道的稳定与破坏影响较大.     

Numerical study of shear behavior of intermittent rock joints with different geometrical parameters

The purpose of this paper is to investigate shear behavior of rock specimens containing several intermittent joints with different geometrical parameters. Through three series of direct shear tests based on rock failure process analysis (RFPA^2D) code, the whole shear failure process is visually observed and the failure patterns in reasonable accordance with other experimental results are obtained. In general, the failure pattern is mostly influenced by the geometrical parameters of rock joints while shear strength is closely related to the failure pattern and its failure mechanism. It is observed that the propagation of wing cracks depends on the joint separation and the joint azimuth angle, and the connection of wing cracks dominates the eventual failure pattern and determines the peak shear load of the rock specimens. The results also show that macro shear fracture is due to the mesoscopic tensile damage of a large number of elements. This numerical study has made a more reasonable theoretical explanation for the shear mechanism of jointed rock due to the inner damages that are difficult to observe in an experimental testing.     

煤层底板下隐伏陷落柱的滞后突水机理

应用有限元数值计算方法,模拟研究了含隐伏陷落柱煤层底板在采动应力扰动和高承压水共同作用下陷落柱活化、裂隙萌生、裂隙扩张、突水通道贯通形成的全过程,通过对损伤场、变形场、应力场和渗流场的解读,对突水通道进行时空基准标定,并就陷落柱发育高度、承压水水压力大小对突水滞后时间的影响进行了分析探讨,从岩体在长期的环境影响、载荷作用下损伤演化、物理力学性能退化的角度,揭示了煤层底板下隐伏陷落柱的滞后突水机理.     

三单位全瓷固定桥破坏机理及过程的数值模拟

针对全瓷桥修复体在临床易发生崩瓷、折裂破坏以及其破坏过程和机理仍不十分明确等问题,采用真实破裂过程分析RFPA 2D系统,模拟了静载荷条件下三单位氧化锆全瓷桥底冠的破坏过程,分析了其破坏机理.应力指纹图和主应力分布图显示全瓷桥的破坏模式属于拉破坏且裂纹最初萌生于全瓷桥连接体下部.对比数值模拟的破坏模式和已有的试验结果,发现二者破坏模式十分吻合.RFPA 2D 能够全程逐步自动追踪全瓷固定桥折裂全过程,该项研究可作为试验研究、临床观察研究、全瓷固定桥抗折裂破坏能力研究的一种重要补充手段.     

有分区破裂化倾向的深部巷道围岩支护分析

在分析总结巷道围岩分区破裂机理研究现状的基础上,阐述了深部岩体特性对巷道破坏和支护的影响,探讨了现有支护荷载理论用于深部岩体工程的局限性。进一步分析了深部巷道支护方法对有分区破裂化倾向的深部巷道围岩的适用性,并针对深部工程的复杂物理力学特性和地质环境条件,提出了动态联合支护理念。     

Limit span of self-anchored cable-stayed suspension cooperation system bridge based on strength

The limit span of self-anchored cable-stayed suspension bridge is deduced. The relations among the geometrical parameters, loads and material characteristics are also analyzed. Based on the material strength and commonly used materials, the limit spans of self-anchored cable-stayed suspension bridges with concrete girder or steel girder under vertical static load are discussed in detail. The corresponding upper limit spans and the effect of the factors on the span are given. The results indicate that increasing rise-span ratio, height-span ratio and cable-stayed segment length or reducing the second dead load could increase the cooperation system span. __________ Translated from Journal of Dalian University of Technology, 2008, 48(3): 387–391 [译自: 大连理工大学学报]     

Limit span of self-anchored cable-stayed suspension cooperation system bridge based on strength

The limit span of self-anchored cable-stayed suspension bridge is deduced. The relations among the geometrical parameters, loads and material characteristics are also analyzed. Based on the material strength and commonly used materials, the limit spans of self-anchored cable-stayed suspension bridges with concrete girder or steel girder under vertical static load are discussed in detail. The corresponding upper limit spans and the effect of the factors on the span are given. The results indicate that increasing rise-span ratio, height-span ratio and cable-stayed segment length or reducing the second dead load could increase the cooperation system span.